The present invention relates to a waste combustion system for burning waste substances for their destruction and, more particularly, to a low-pollution waste combustion system that is capable of effecting high-load combustion while satisfying various regulation standards of exhaust gases as set forth in the Air Pollution Control Law.
Waste combustion systems of various types have been known, and they include stokers, fluidized bed furnaces, and rotary kilns. Such conventional systems are provided with an arrangement for promoting the burning of waste. As shown in FIG. 2, a standing oil burner A, which mainly uses heavy oil, is provided. Primary air, necessary for combustion, is supplied from the bottom floor surface and/or a lower inner surface of the furnace body, and secondary combustion air nozzles B are provided downstream of the standing oil burner A so that secondary combustion air is mixed with the primary combustion gases. The resultant gas mixture is led to a secondary combustion chamber C. With this arrangement, the system performs hightemperature combustion of, above all, highly calorific waste, which has recently become common.
Measures are taken to prevent air pollution by exhaust gases emitted from the chimney stack. As shown in FIGS. 3 to 5, the exhaust gases resulting from combustion are first cooled by water spray from an upper position within the furnace. Further, various components of the exhaust gases are subjected to various necessary post-treatments.
In general, therefore, combustion systems have become large in size and complicated in structure. Yet, they still fail to meet certain requirements. For instance, the durability of the furnace, or their ability to prevent air pollution is not satisfactory.